Impacts of nonnative species on the health of natural and planted forests
Despite conservation eorts, most forest ecosystems worldwide are aected by biotic invasions; however, the specific impacts vary across dierent geographic regions and forest types. The relative contributions of the main drivers such as propagule pressure (e.g., due to human population, travel, and trade), climate, land use, and habitat invasibility remain uncertain. The special issue “Impacts of Nonnative Species on the Health of Natural and Planted Forests” was organized to facilitate timely communications among scientists and managers in dierent regions and to assist in attempts to improve forest health and maintain long-term sustainability. The special issue addresses broad issues related to forest invasions, including the impacts of nonnative species in various forest ecosystems (e.g., natural vs. urban) and the contributions of land use (e.g., fragmentation), human activity, and climate change to invasion. The new findings include identifying hotspots of potential invasion impacts and their causes, which can help inform policy makers as they develop eective strategies for prevention, early detection or eradication, and forest management.